Process for producing 1 amino 2, 3 dicyano 4 oxyalkylamino anthraquinones



Patented Nov. 1 6, 1 951 PROCESS FOR PRODUCING 1 AMINO 2,3 DI- CYANO 4OXYALKYLAMINO ANTHRAQUI- NONES I Victor S. Salvin, Irvington, and JohnR. Adams,

Jr., Summit, N. J., assignors to Celanese Corporation of America, NewYork, N. Y., a corporation of Delaware No Drawing. Application July 1,1950,

Serial No. 171,756

11 Claims. (01.260-379) 1 This invention relates to anthraquinonedyestuffs and relates more particularly to an improved process for theproduction of certain novel anthraquinone dyestuffs of the generalformula:

OI NH:

wherein n is an integer from 1 to 5 and X is an alkyl or hydroxyalkylgroup. Examples of alkyl groups which may be present in said dyestufiare the methyl, ethyl, propyl and isopropyl groups, While examples ofhydroxyalkyl groups are hydroxymethyl, hydroxyethyl, hydroxypropyl andhydroxyisopropyl groups. These novel dyestuffs dye cellulose acetate andother organic derivative of cellulose materials in valuable blue shadesexhibiting a satisfactory resistance to acid fading.

The present application is a continuation-inpart of our copendingapplications Ser. No. 115,768, filed September 14, 1949, and Ser. No.136,650, filed January 3, 1950.

The anthraquinone dyestufi's, described above and which form the basisof said copending applications, have heretofore been obtained byreacting the compound 1-amino-2-sulfo-4-bromoanthraquinone with anhydroxyalkoxyalkyl amine or alkoxyalkylamine of the formula so that the4-brom substituent is replaced by the amine, purifying theamino-anthraquinone intermediate by washing or the like, and thenreacting the said intermediate with an alkali metal cyanide whereby acyano group replaces the 2-sulfo group and a second cyano group entersin the 3-position. The dyestuff precipitates from the reaction mixtureand, after being filtered out, is subjected to a purification treatmentbefore it is ready for use. As carried out heretofore, this processproduced a relatively low yield of the desired dyestuff and was,therefore, not wholly suited for commercial use.

It is an important object of this invention to provide a process forpreparing the aforementioned anthraquinone dyestuffs which will be freefrom the foregoing andother disadvantages of the processes previouslyused for this purpose.

A further object of this invention is to provide a process for preparingthe aforementioned anthraquinone dyestuffs whereby the dyestufis areobtained in a high yield and in a high degree of purity.

Other objects of this invention will appear fromv the following detaileddescription and claims. According to the present invention,anthraquinone dyestufis of the formula wherein n is an integer from 1 to5 and X is an alkyl or hydroxyalkyl group are obtained in significantlyimproved yields by carrying out the initial amination of the compound1-amino-2- sulfo-l-bromoanthraquinone, wherein the 4-brom group isreplaced, in a medium containing an acid binding agent, removing theexcess amine from the reaction mixture, and efiecting the cyajnation ofthe intermediate so formed in a medium maintained at a pH of about 9.6to 10.1.

Thus, in carrying out the process of the instant invention,1-amino-2-sulfo-4-bromoanthraquinone is reacted with ahydroxyalkoxyamine or alkoxyalkylamine in an aqueous medium containingabout 0.5 to 3 mols of an acid binding agent for each mol of theanthraquinone undergoing reaction, employing a reaction temperature ofabout to C. and a reaction period of about 2 to 8 hours. Suitable acidbinding agents include alkali metal carbonates such as sodium carbonate,potassium carbonate, sodium bicarbonate, or the like. Preferably foreach mol of the 1 amino 2 sulfo 4 bromoanthraquinone, there is employedabout 2 to 6 mols of the hydroxyalkoxyalkylamine or alkoxyalkylamine.The presence of the acid binding agent shortens the reaction period andreduces the amount of amine required, and also improves the yield andpurity of the amino-anthraquinone intermediate.

To catalyze the amination reaction, there may be employed cupricacetate, cupric chloride, 'or activated copper powder. The catalyst isusually employed in an amount of from about 0.025 to 0.1 mol for eachmol of the anthraquinone undergoing reaction. After the amination iscomplete, the reaction mixture is filtered to remove any solids and thefiltrate is vacuum distilled to remove the excess amine. The residue ofthe vacuum'distillation may then be employed directly from the cyanationreaction since it contains only negligible quantities of impurities, or,if desired, the residue may be dissolved and the solution acidified withhydrochloric acidso as to precipitate the amino-.anthraquinoneintermediate therefrom as the hydrochloride. The precipitate is filteredand then washed with dilute hydrochloric acid further to purify thesame.

The cyanation is carriedout-byldissolvingthe amino-anthraquinoneintermediate in water'and adding to the solution an alkali metal cyanideand a sufficient amount of a buffer-salt to bring the pH to about 9.6 to10.1. The reaction mixture is then heated to a temperature ,of about 70to 90 C. for about 8 to 24 hours, with periodic additions of the buffer,if necessary, to maintain the pH at about 9.6 to 10.1. The "2-sulfogro,u p is replaced by a cyano group during the above reaction and asecond cyano group is also introduced in the 3-position. As the dyestuffis iiormedii re ipit esirozn thes luticnandmay be recovered byfiltration. By maintaining the 'eyana qn a t on m x ure a pHor about.9.6 it! 3 .1, :th spe of th rea tion and the yi ld and purity of thedyestufi are improved.

fixaznple .Q tsui abl ufier salts are alkali metal dihydrogen phosphates.suchas sodium .or potassium dihydrogen phosphate, the sodium orpotassium salts of citric or'boric acid, or the like. Periodic additionsof the foregoing salts to the reaction mixture are necessary to maintainthe pH between the desiredilimits. iAdvantageously, however, there isemployedasabufier salt an alkali metal bicarbonate such as sodiumbicarbonate, potassium'bicarbonate, or the like, since a ;singleaddition of the bicarbonate serves effectively .to maintain the pHbetween thedesired limitss during ,the entire reaction.

The following examples are given .to ilustrate .thisinvention further.

Example I mixture of 4. .parts by weight of l-amino- 2.,- sulfo-4-bromoanthraquinone, parts by weight of sodium carbonate, ,1 part byweight'of upric acetate and 4 5 parts by weight offi-methoxyethylamineisdissolve'din 330 parts by weight of water andheated .withstirring at 80 C. for Bi -hours. The solution is filteredandheated under vacuum to rem ve water and excess amine which ay be sed aai r hea n r a tion. The residue from the vacuum distillation isdissolved in.500 parts by weight of .water and the solution brought topII .7 with about llparts by weight of 36.5% hydrochloric acid. Anadditional 7.1 parts by weight of 36.5% hydrochloric acid is added tothe solution, precipitating the hydrochloride of,1-aminoe2-sulfo-2-p-methoxyethylaminoanthraquinone, which is filteredwith suctionand washed twice with 3% hydrochloric acid. There isobtained 40 parts by weight of the intermediate or 82% of theoretical.

There is added to 80 0 parts by weightof water, 36 parts by weight ofthe hydrochloride of 1- amino 2 sulfo-4-p-methoxyethy1aminoanthrauinonetogether with 8 parts by weight of sodium bicarbonate to bring the pH ofthe solution to 7 m9 and causethe-hydrochlorideto dissolve. To thesolution there are added parts by weight of sodium cyanide and 16 partsby 1 weight of-potassium dihydrogen phosphate. The .pH-of the solutionis 9.7. The solution is heated ;to ;80 C. for 11 hours withperiodicadditions of potassium dihydrogen phosphate to maintain a pH ofabout 9.6 to 10.1. At the completion of 4 the reaction, the mixture iscooled and the precipitated dyestufi filtered ofi. There is obtained 23parts by weight of the dyestufi vgrin-0H1-orn-o-orn or 7.6% oftheoretical based on the intermediate.

Example II .There isiadded ,to 800 parts by weight of water, 36 parts byweight of the residue from the vacuum distillation of the1-amino-2-sulfo-4-pmethoxy-ethylaminoanthraquinone as preparediniExample I, together with 25 parts by weight of sodium cyanide and 12parts by weight of sodium bicarbonate. The .pH of the solutions is 9.65.The solution heated, with. stirring; to.'8,0 C. vfor1.1.hourSQ-durinQwhiiihtimethe pHrises to 10.1. At .th eicornpletiomof'theieaction, the mixture .is cooled and the precipitated'dyestufffiltered off. There is obtained 27 partsby weight of the dyestufiwherein n is an integer from '1 to 5 and X is a me ber of-the: g u wns sin i kyla dn ydroxyallgyl groups .to {a -,cyanation reaction with analkali metal cyanide in -.a medium :having .a pH-pf a outfiifi t 110.11.

In .a process {or the Production ;of anthraquino l =dyestufis, ,the stepwhich comprises :subg'ecting .an intermediate i the formula .wherein nis.anintegerjfrom .1 .to .5 and X is :a member ;of .the.group onsistingoialkyl and-hydrqxyalkyl groups to alcyanation reaction with na tal-eya idn mediu e t .a .hufiensalt to .bring ithepH to about 19.6 to 10.1.

.3. a process .iior the production of anthraquinone dyestuifs, the stepwhich comprises subjecting an intermediate-of the formula I NHz whereinn is an integer from 1 to 5 and X is a member of the group consisting ofalkyl and hydroxyalkyl groups to a cyanation reaction with an alkalimetal cyanide in a medium containing an alkali metal bicarbonate tobring the pH to about 9.6 to 10.1.

5. In a process for the production of anthraquinone dyestuffs, the stepwhich comprises subjecting an intermediate of the formula Ol NHz whereinn is an integer from 1 to 5 and X is a member of the group consisting ofalkyl and hydroxyalkyl groups to a cyanation reaction with an alkalimetal cyanide in a medium containing sodium bicarbonate to bring the pHto about 9.6

i to 10.1, said reaction being carried out at a temperature of 70 to 90C. for a period of 8 to 24 hours.

6. In a process for the production of anthraquinone dyestuffs, the stepwhich comprises subjecting an intermediate of the formula OI NH:

wherein n is an integer from 1 to 5 and X is a member of the groupconsisting of alkyl and hydroxyalky groups to a cyanation reaction withan alkali metal cyanide in a medium containing an alkali metaldihydrogen phosphate to bring the pH to about 9.6 to 10.1, and addingfurther quantities of alkali metal dihydrogen phosphate to the mediumduring the reaction to maintain the pH at about 9.6 to 10.1.

7. In a process for the production of anthrah NHz Y N'H--(OHz),.O-Xwherein n is an integer from 1 to 5 and X is a member of the groupconsisting of alkyl and hydroxyalkyl groups to a cyanation reaction withan alkali metal cyanide in a medium containing potassium dihydrogenphosphate to bring the pH to. about 9.6lto 10.1, and adding furtherquantities of potassium dihydrogen phosphate to the medium during thereaction to maintain the pH at about 9.6 to 10.1, said reaction beingcarried out at a temperature of '70 to C. for a period of 8 to 24 hours.

8. In a process for the production of anthraquinone dyestufis, the stepswhich comprise reacting l-amino 2- sulfo -4- bromoanthraquinone with anamine of the formula wherein n is an integer from 1 to 5 and X is amember of the group consisting of alkyl and hydroxyalkyl groups in thepresence of an acid binding agent to form an intermediate, distillingany excess amine from the reaction mixture, and subjecting the residueof the distillation to a cyanation reaction with an alkali metal cyanidein a medium having a pH of about 9.6 to 10.1.

9. In a process for the production of anthraquinone dyestufis, the stepswhich comprise reacting l-amino- 2 -sulfo- 4 -bromoanthraquinone with anamine of the formula wherein n is an integer from 1 to 5 and X is amember of the group consisting of alkyl and hydroxyalkyl groups in thepresence of sodium carbonate, said reaction being carried out at atemperature of '75 to 90 C. for a period of 2 to 8" hours to form areaction mixture containing an intermediate, and subjecting the reactionmixture containing said intermediate to a cyanation reaction with analkali metal cyanide in a medium containing sodium bicarbonate to bringthe pH to about 9.6. to 10.1, said reaction being carried out at atemperature of '70 to 90 C. for a period of 8 to 24 hours.

10. In a process for the production of anthraquinone dyestuffs, thesteps which comprise reacting 1-amino-Z-sulfo-4-bromoanthraquinone withan amine of the formula wherein n is an integer from 1 to 5 and X is amember of the group consisting of alkyl and hydroxyalkyl groups in thepresence of sodium carbonate, said reaction being carried out at atemperature of '75 to 90 C. for a period of 2 to 8 hours to form areaction mixture containing an intermediate, and subjecting the reactionmixture containing said intermediate to a cyanation reaction with analkali metal cyanide in a medium containing potassium dihydrogenphosphate to bring the pH to about 9.6 to 10.1, and adding furtherquantities of potassium dihydrogen phosphate to the medium during thereaction to maintain the pH at about 9.6 to 10.1, said reaction beingcarried out at a temperature of 70 to 90 C. for a period of 8 to 24hours.

ammo

a process-for the production of anthraquinone dyestufis, the steps whichcomprise reacting l-amino- 2 -sulfo-'4-bromoanthraquinone withp-methoxyethylamine in an aqueous medium containing sodium carbonate,said reaction being carried out at a temperature of 80 C. for a periodof three hours to produce an intermediate, distilling water and anyexcess amine from the reaction mixture, and subjecting the residue ofthe distillation to a cyanation reaction with sodium cyanide in anaqueous medium containing sodium bicarbonate to bring the pH to about9.6 to 10.1

VICTOR S. SALVIN. JOHN R. ADAMS, JR.

til

REFERENCES CITED UNITED STATES ,PA'IEN'I'S Number Name Date 1,938,029Kugel Dec. 5, 1933 2,357,176 Dickey Aug. 29, 1944 2,496,414 Seymour Feb.7, 1950 FOREIGN PATENTS Number I Country Date 306,963 Great Britain May2'7, 1930 309,454 Great Britain July 10', 1930 512,483 Great BritainSept. 18, 1939 Certificate of Correction Patent No. 2,573,811 November6, 1951 VICTOR S. SALVIN ET AL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requirlng correction as follows:

Column 3, line 58, for -2-sulfo-2-;3- read -2-suZf0-4-B-;

and that the said Letters Patent should be read as corrected above, sothat the same may conform to the record of the case in the PatentOflice.

Signed and sealed this 12th day of February, A. D. 1952.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

1. IN A PROCESS FOR THE PRODUCTION OF ANTHRAQUINONE DYESTUFFS, THE STEPSWHICH COMPRISES SUBJECTING ANINTERMEDIATE OF THE FORMULA